Silencer for multicylinder internal-combustion engines



July 14, 1925.

K. STAHL SILENGER FOR MULTICYLINDER INTERNAL COMBUSTION ENGINES FiledJune 28, 1920 INVENTOR:

Patented July 14, 1925.

UNITED STATES 1,546,262 PATENT OFFICE.

KARL STAHL, OF FRIEDBICHSHAFEN, GERMANY, ASSIGNOB TO THE FIRM: LUFT-SCHIFFBAU ZEPPELIN, GESELLSCHAFT MIT BESCHRANKTEB HAF'IUNG, OF FRIED-BICHSHAFEN, GERMANY.

SILENCEB FOB. IULTICYLINDER INTERNAL-COMBUSTION ENGINE.

, Application filed June 28, 1920. serial No. 392,005.

To all whom it may concem:

Be it known that-I, KARL STAHL, a citizen of Germany, residing atFriedrichshafen, Germany, have invented certain new and usefulImprovements in Silencers for Multicylinder Internal-Combustion Engines,of which the following is a specification.

My invention refers to multicylinder internal-combustion engines, andmore especially to the silencers thereof. Silencers, as everybody knows,are employed in order to make it possible to discharge exhaust gaseswithout troublesome increase in pressure with as little noise aspossible and at a low temperature. For this purpose it is necessaryabove all to reduce the volume of the exhaust gases by cooling and toavoid all unnecessary resistance in doin so by conducting the exhaustgases an the cooling medium in an appro riate manner.

My invention achieves this object in a particularly advantageous mannerinasmuch as the whole of the conduit-piping which connects the flangedexhaust sockets of the various cylinders with some system of mixing andcooling nozzles which as much is already known, is encircled by the samecurrent of coohn air which is also fed to the nozzles. In tie aboveevery individual exhaust pipe coming from any one cylinder (or theother) may be enclosed in aseparate cooling pi e and all the exhaustpipes and all the coo ing plipes can fina1lebe united to form one jointollow body. tter results, however, are gained, ifthe whole of theconduit-piping is enclosed in one joint casing which is open in thevicinity of the flanged exhaust sockets.

A particularly simple silencer is attained in accordance with minvention by not leading the exhaust pipes of the various cylinders tothe mixlng space se arately, but by uniting them in a joint con nit-pipecasing shortly after leaving the flanged exhaust sockets. In accordancewith the invention the latter, for the purpose of further increasing thecooling effect, may be equipped on the outside with radiator projectionsprojecting into the space through which the cooling air flows and at thesame time serving to guide the air provided they are designed tocorrespond to the streamlines as far as possible.

In the drawings attached to this specificat1on and forming part thereof,a silencer in accordance with the invention is illustrated by way ofexample.

In the drawings Fig. 1 is a cross-section of a silencer in the plane ofsymmetry 11 of Fig. 2 whilst Fig. 2 is a cross-section in the plane 22of Fig. l and Fi a view from the front, part of who is shown as acrossesection in the plane 33 of Fig. 1. Fig. 4 is a section on the lineIVIV in Fig. 2.

The silencer consists of a conduit-pipe casing A, conducting the exhaustgases, and an outer casing B. In the case exemplified the conduit-picasing A is subdivided in the vicinity o the entranceside of theexhaustgases into six entrance pipes, a correspondlng to the variouscylinders. The conduit-pipes end in a flange-plate a for fastening whichmakes it possible to connect u with the six exhaust openings of the 'cyinders not shown in the drawing. The real conduit-pipe casing A as wellas the entrance pi es a branching oil from it, but situated within theouter casing B are fitted with a number of radiator projections a Thelatter partly also serve to stay the outer casing B against theconduitpipe casing A. At a the conduit-pipe casmg A o ens into the firstof four cooling nozzles in which the mixing of the exhaust gases withair takes place at the same time. The outer casing B does not connect uptight with the flange plate a for fastening, but leaves aspace 6' openall around as an entrance for the air. At the other end the outer casingB connects up with the easing D of a mixer which, however, does not formthe object of the invention.

The form of the whole silencer casin can vary widely according to thenumber 0 cylinders and type of motor employed. The connection with a secial mixer casing for the purpose of furt er deadening the noise is notabsolutely necessary. For reasons of simplifying the drawing it isassumed that the silencer has a plane for its surface of symmetry. Inthe case of a construction for practical use it is advisable to deflectat least the part containing the nozzle arran ement in such a wa as tomake the total sur ace of resistance 0 the exterior become as small aspossible and to render it possible to lead the exhaust ases as well asthe cooling air mixed with them, further in a direction opposite to thatin which the craft or conveyance is moving. Especially in the case ofsilencers for internal-combustion engines of air-craft it is recommendedto shorten the various entrance pipes very much or to cut them outentirely and to lead an undivided conduit-pipe casing up to just infront of the flange-plate for fastening instead.

Of course the arrangement may also be de-' tube and an open-endedtapered jacket spaced apart from said plate so as to offer asubstantially annular air inlet, said jacket surrounding with aclearance all said single pipes, said tube and said nozzles.

2. In a'silencer for multicylinder internal combustion engines incombination, a plurality of exhaust pipes united to form a singleconduit, a pluralitv of air nozzles disposed in series to the rear ofsaid conduit, ribs on said pipes and an open jacket surrounding with aclearance all said pipes, said conduit and said nozzles.

3. In a silencer for multicylinder internal combustion engines incombination, a plurality of exhaust pipes united to form a singleconduit, a plurality of air nozzles disposed in series to the rear ofsaid conduit, ribs on said pipes and said conduit and an open jacketsurrounding with a clearance all said pipes, said conduit and saidnozzles.

In testimony whereof I aflix my signature.

KARL STAHL.

